What follows is a slightly altered version of a two-part series of posts I recently wrote, now combined as my entry for Pussy Goes Grrr's Juxtaposition Blogathon:
In the realm of categories, black is always marked as a color [...], and is always particularizing; whereas white is not anything really, not an identity, not a particularizing quality, because it is everything -- white is no color because it is all colors. This property of whiteness, to be everything and nothing, is the source of its representational power.
-- p. 127, Richard Dyer's "White" from The Matter of Images
Reading Dyer's above quoted essay reminded me of the classic Saturday Night Live skit where Eddie Murphy went undercover as a white man to discover what whiteness is really like. He receives a free newspaper, gets cash from a bank without any credit and, once the city bus is free of minorities, the whites have a party. Instead of whiteness being the default or normative position from which every other ethnicity is otherness, Murphy's blackness is the norm and whiteness is seen as excess.
A less ironic and more recent example of what Dyer's getting at is the colorizing of Marvel's superheroes: Nick Fury is black in the films and Ultimate line; the Ultimate version of Peter Parker was killed off and replaced by a half black, half latino kid named Miles Morales; Kingpin was played by a black man in the Daredevil film; and more controversial among the Aryan supremacists was the decision to make the Norse god Heimdall black in the Thor film. The difference here between whiteness and otherness is that Peter Parker isn't first marked as white, second as Spider-Man, but Miles Morales is foremost a mixed ethnicity and secondly a superpowered human. If he were to live with his aunt at a near poverty level, that would be part of his ethnic narrative, whereas it's not really a part of Peter's being white. For Peter, those are qualities which merely help the audience sympathize with his struggle as an individual (they aren't anything but dramatic attributes within a particular narrative). The white narrative, through its dominance, seen as normative, is hidden, only revealed by contrast with what falls outside, or underneath.